A common means of providing for the focussing of cameras, such focussing requiring motion of the lens housing with respect to the film plane, is to fit to a lens housing a rotatable disk having circular slots arranged upon an arc of a circle, said slots being penetrated by metal rivets. The metal rivets clamp the disk against accidental rotation, and displacement of the lens housing. The camera is adjusted by rotating the regular plate with the aid of teeth on the periphery thereof. The rivets are of metal, as aforenoted, and the contact pressure between the rivet and the regulating plate, and the consequent resistance to rotation, are difficult to maintain within appropriate limits.
The conventional mechanism, involving as it does the relatively sensitive lens housing, is both difficult and expensive to execute. Also, as aforenoted, it is difficult to hold the contact pressure to the required narrow tolerance. Nevertheless, a means for adjusting the position of a variety of components within a camera body is needed where the means is such that the components can be moved relative to each other without too much difficulty and yet which is such that the components will remain in the selected position despite accidental disturbance. Further, the means should be inexpensive, easy to fabricate, and safe to use in combination with the sensitive lens housing and compact. Moreover, the design should be such that it can be carried out on a production scale.